SubordinateClause is the class of clauses that cannot stand on their own as sentences. A matrix clause combined with a subordinate clause form a main clause. In the sentence 'John thinks that Mary is sick', 'Mary is sick' is the subordinate clause.

The relation hasConstituent is an abstract partial ordering relation that expresses dominance between two linguistic units. This relation is meant to cover all possible types of linguistic constituency: phonological, morphological, syntactic, etc. constituency.

The relation hasSyntacticConstituent is an abstract partial ordering relation that expresses dominance between two syntactic units. This relation is meant to cover all possible types of syntactic constituency.